Starting issue/Safety Switch?
 

1994 "88" is simply not engaging the starter intermittently. I have replaced the starter and lead cable. Still it only seems to turn over when it wants to. I am thinking perhaps Neutral Safety Switch or something with the Security. I can't see how the N.S.S. would fail one minute and work the next, but it is 20 y/o electronics. So here are my ???'s: What is the location of the N.S.S. and can it be bypassed? Similarly, is there any way to disable the security system?

First check the battery cable connections at the battery, that they are clean and tight.....also the connections at the starter solenoid....

Is there a black resistor pellet on your ignition key?

If yes, when you turn your key to "on", does your SECURITY LIGHT go out after 3-5 seconds?

If it does, and then you turn your key to the crank position, and the engine doesn't crank, I would check your starter enable relay.....try swapping with another relay.....

IF the light doesn't go out, then you could have an intermittent problem with the wiring harness to the ignition lock cylinder....

Your neutral safety switch is located on top of the tranny where your cable attaches to the shift lever......the PassKey module grounds the starter enable relay(if the SECURITY LIGHT goes out), which then sends power to the starter.....

https://www.gmforum.com/attachment.p...ine=1418353985

Ruled out the N.S.S. its something with the security. And I am glad starter relay was brought up. Because, the car has been fine for the last several days, but yesterday when the temps dropped, no start! So I am thinking cold is causing this. Could the relay be stickiing/shrinking?

If your key has the little black pellet on it I'm thinking it as a wire that is broke in the Ign cylinder. Very common issue with the VATs system. Many people choose to bypass the lock cylinder by adding a resistor that is the same value as the one in your key under the dash.

I looked up how to bypass VATS. And plan on doing just for preventative maint. BUT BUT BUT,,, temperature is playing a role in this. So I have to look into the starter relay. Is that withing the relay bank and hopefully marked???

i think the are pretty well hidden up under the drivers foot area. havent personally worked on one but i think i remember a few folks that said that was were they found it

Check this out.... decided to bypass vats just in case. followed instructions to a T. Car fired right up but security light stayed on. Started and shut of several times. So then I disconnected the resistor loop just see what would happen, the dumb car still started!! I decided to properly put the new connection together and see how long before I had a problem. Get that all done, start the car, NO security light. Put 100mi on it tonight. I think it worked!!! My question is, could the computer maybe has been stuck in that security mode since I was monkeying around and maybe needed to calibrate?

if its withing the window for resistance tolerance, it shouldnt be any different than the key. so maybe it wasn't connected that well the first time.

From what I understand, if the TDM detects there is an issue, which it only does under certain circumstances, it will allow the car to start fine without the proper feedback, but the security light will be on while this is happening. I assume it then went out because it is now getting proper resistance, or something happened with the light, but you should be able to see it flash and go out now.

I agree with the guys.....it was probably a bad connection, which you repaired....